Field of the Invention
The invention relates to a panel-like, manufactured wood-based material for furniture and interior construction, offering attractive, decorative alternatives to conventionally applied finishes in numerous possible variations.
Description of the Prior Art
Wood-based materials, such as chip or particle board, oriented-strand board (OSB) or board featuring a homogeneous structure in all directions and known as high-density fiber board (HDF) or medium-density fiber board (MDF) are by far the most widely used materials in furniture and interior construction, as well as in construction for trade shows, theater stage scenery, and small shops. The panels, which contain wood shavings or wood fibers or both, are typically produced in a dry process and a binder that is adapted to the final intended use of the panels is generally added during production. Special additives may impart properties to the material, such as reduced water absorption and, thus, reduced thickness swelling, low flammability and/or a certain resistance to biological pests and environmental damage.
These wood-based board products provide advantages for their particular application. Particle board and MDF board panels, however, have a distinctly unattractive surfaces, and, for this reason, are usually faced or coated with other materials, preferably veneers, synthetic materials, and varnishes. Recently, manufacturers have succeeded in manufacturing MDF that is imbued or colored all the way through, with very good reproducibility of all quality parameters (see on the Internet: MASTERWOOD black, from the company Hornitex; TOPAN black/brown, from the company Glunz; TOPAN color FF from the company BASF/Glunz). The melanine resin-coated Hornitex product ”M.D.F. Masterwood black“, for example, is considered a high-value substitute for solid wood and a base material for surface treatments which had previously been done very little, such as direct varnishing, foiling, coating, encasing, and veneering, whereby now the decorative bond between foil and melamine from the front and rear faces up to the corpus, edge and layer material is now ensured.
This through-colored MDF, however, satisfies only to a limited degree the requirements of architects and designers, to show the inherent structure of the material, without subsequent decorative coating, and to let the material itself have an effect. Constant progress has been made in recent years in this regard with OSB (oriented strand board), which was introduced into Europe at the beginning of the 90s. These multi-layer panels, made with 12 cm long, slender, longitudinally oriented strands of a pre-defined form and thickness, stand out, not only because of their higher bending strength compared to standard flat-pressed boards (particle boards), but also because of a characteristic appearance which is due to the bonding and strand structure. Owing to its “woody” appearance, the typical OSB structure (large-surface structure of the wood shavings) is appreciated as a decorative element.
Furthermore, in recent times the surfaces of the OSB panels are also being dyed (see on the Internet: Agepan OSB color, from the company Glunz; Eurostrand OSB Dekorativ, from the company Egger). The uniform areal coverage after multiple applications of UV special varnishes or paints is just intense enough to clearly emphasize overall the chosen color, on the one hand, but on the other hand, is done intentionally to not blot out the random beauty of the long strands. The strands must be light in color, however, for the board material to show this desired important effect.
U.S. Pat. No. 4,109,041 discloses a construction panel in which elastomeric particles, preferably rubber grindings and buffings produced in vehicular tire manufacturing and recapping operations, are incorporated into at least one surface of particle board panels. It is the objective of the invention to increase the roughness of the panel surface, so that they can be stacked without problem, tools can be safely placed on such panels, and to increase safety when stepping on these panels. The addition of elastomeric particles also creates (unintentionally) a new, decorative construction panel that differs from the conventional structure of particle board panels. It is essential that the structure of the panel surface be smooth and, in particular, that the elastomeric particles be uniformly distributed. Thus this “decorative” panel, which was exclusively developed for use as a construction panel with a non-skid property, can by no means meet the above-mentioned requirements for a decorative wood-based panel intended for furniture and interior construction purposes.
Furthermore, U.S. Pat. No. 3,887,415 discloses a wood-based panel, which has a protective layer made of bark shavings. Its surface is harder than the natural, weathered bark of a tree and gives the panel a marbled and structured surface with a decorative appearance. Essential to the invention is that the bark shavings be bonded under pressure to form a single layer of material, which is then sanded to remove any projections. Overall, the effort required to make such a panel is comparatively high, because it requires a two-stage process. Consequently, this proposal has remained prior art on paper.
The prior art for decorative wood-based panels that are usable without facings is, thus, in practice defined by the surface color treatment with OSB and the smooth single-color construction of through-colored MDF. Both methods, despite their advantages, are resource-intensive and costly. Unfaced wood-based panel materials featuring a decoratively structured surfaces that exceed the (moderately satisfactory) effects achieved by means of light-colored strands, are not known. The solutions described in the above-mentioned US patents either do not satisfy the aesthetic requirements because they were developed for other purposes (U.S. Pat. No. 4,109,041), or they permit a bark-type decoration only (U.S. Pat. No. 3,887,415). Furthermore, they are technologically very resource-intensive.